Investors should carefully consider the investment objectives, risks, charges and expenses of a Harbor fund before investing. A summary prospectus or prospectus for this and other information is available at harborfunds.com or by calling 800-422-1050. Read it carefully before investing.

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Subject to an expense limitation agreement (excluding interest expense, if any) through February 29, 2020

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.80%, 0.72%, 1.05%, and 1.17% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

Restated to reflect current fees.

Subject to a contractual management fee waiver and an expense limitation agreement, excluding interest expense, if any, through February 29, 2020.

Interest expense for the fiscal year ended October 31, 2018 was 0.29%

Subject to an expense limitation agreement (excluding interest expense, if any) through February 29, 2020

Interest expense for the fiscal year ended October 31, 2018 was 0.63%

Subject to a contractual management fee waiver through February 29, 2020

Subject to an expense limitation agreement (excluding interest expense, if any) through February 29, 2020

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.45% and 0.37% for the Institutional Class and Retirement Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Based on estimates for the current fiscal year.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.52%, 0.44% and 0.77% for the Institutional Class, Retirement Class and Administrative Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 1.15%, 1.07%, 1.40%, and 1.52% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.90%, 0.82%, 1.15%, and 1.27% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.95%, 0.87%, 1.20%, and 1.32% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.85%, 0.77%, 1.10%, and 1.22% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.80%, 0.72%, 1.05%, and 1.17% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.73%, 0.65%, 0.98%, and 1.10% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Based on estimated amounts for the current fiscal year.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.88%, 0.80%, 1.13%, and 1.25% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class, respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Based on estimated amounts for the current fiscal year.

The Adviser has contractually agreed to reduce the management fee to 0.60% through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.70%, 0.62%, 0.95%, and 1.07% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class, respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any) to 0.70%, 0.62%, 0.95%, and 1.07% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class, respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The percentage of the Fund's total assets invested in securities that can be converted into cash within one business day. Regulations require that a money market mutual fund hold at least 10% of its total assets in daily liquid assets.

The percentage of the Fund's total assets invested in securities that can be converted into cash within five business days. Regulations require that a money market mutual fund hold at least 30% of its total assets in weekly liquid assets.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.95%, 0.87%, 1.20%, and 1.32% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 1.15%, 1.07%, 1.40%, and 1.52% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.90%, 0.82%, 1.15%, and 1.27% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.85%, 0.77%, 1.10%, and 1.22% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to reduce the management fee to 0.70% on assets between $350 million and $1 billion and 0.65% on assets over $1 billion through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to reduce the management fee to 0.70% on assets between $350 million and $1 billion and 0.65% on assets over $1 billion through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.68%, 0.60%, 0.93%, and 1.05% for the Institutional Class, Retirement Class, Administrative Class, and Investor Class respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to reduce the management fee to 0.60% through February 28, 2017. Additionally, the Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.80% and 1.05% for the Institutional Class and Administrative Class, respectively, through February 28, 2017. Only the Board of Trustees may modify or terminate these agreements.

Restated to reflect current fees.

The Adviser has contractually agreed to reduce the management fee to 0.60% through February 28, 2017. Additionally, the Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.80% and 1.05% for the Institutional Class and Administrative Class, respectively, through February 28, 2017. Only the Board of Trustees may modify or terminate these agreements.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.94% and 1.19% for the Institutional Class and Administrative Class, respectively, through February 28, 2018. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to reduce the management fee to 0.508% through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.52%, 0.44% and 0.77% for the Institutional Class, Retirement Class and Administrative Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to reduce the management fee to 0.18% through February 29, 2020. Additionally, the Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.28% and 0.53% for the Institutional Class and Administrative Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

Subject to a contractual management fee waiver, and an expense limitation agreement (excluding interest expense, if any) through February 29, 2020

The management fee rate is 0.75% on assets up to $12 billion and 0.65% on assets in excess of $12 billion. The Adviser has contractually agreed to reduce the management fee to 0.63% on assets between $24 billion and $36 billion, and to 0.58% on assets between $36 billion and $48 billion and 0.57% on assets over $48 billion through February 28, 2019. In addition, the Adviser has contractually agreed to further waive a portion of its management fee such that the Fund's operating expenses, excluding interest expense (if any), are limited to 0.72%, 0.97%, 1.09% and 0.64% for the Institutional Class, Administrative Class, Investor Class and Retirement Class, respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.94% and 1.19% for the Institutional Class and Administrative Class, respectively, through February 28, 2018. Only the Fund's Board of Trustees may modify or terminate this agreement.

Represents the average daily dividends for 30 days, assuming all dividends are reinvested, annualized by 365 days and divided by the net asset value per share at the end of the period. Does not reflect reimbursements or fee waivers currently in effect.

The Adviser has contractually agreed to reduce the management fee to 0.56% on assets between $5 billion and $10 billion, 0.54% on assets between $10 billion and $20 billion, and 0.53% on assets over $20 billion through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

Represents the average daily dividends for the last seven days, assuming all dividends are reinvested, annualized by 365 days and divided by the net asset value per share at the end of the period. Does not reflect reimbursements or waivers currently in effect.

Ex-Date. The date on which a Fund's net asset value (NAV) will fall by an amount equal to the dividend and/or capital gain distribution plus or minus any change in the value of the Fund's holdings.

About Expense Ratios: All mutual funds have expense ratios which represent what shareholders pay for operating expenses and management fees. Expense ratios are expressed as an annualized percentage of a fund's average net assets paid out in expenses. Net expense ratios reflect adjustments due to voluntary or contractual fee waivers or expense reimbursements. Expense ratio information is as of the Fund's current prospectus, as revised and supplemented from time to time.

The Adviser has contractually agreed to reduce the management fee to 0.508% through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Represents the average daily dividends for 30 days, annualized by 365 days and divided by the net asset value per share at the end of the period. Reflects reimbursements or fee waivers currently in effect.

The Adviser has contractually agreed to reduce the management fee to 0.56% on assets between $5 billion and $10 billion, 0.54% on assets between $10 billion and $20 billion, and 0.53% on assets over $20 billion through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to reduce the management fee to 0.43% on assets between $1 billion and $3 billion and 0.405% on assets greater than $3 billion through February 29, 2020. Additionally, the Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.51%, 0.43% and 0.76% for the Institutional Class, Retirement Class, and Administrative Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

The Adviser has contractually agreed to reduce the management fee to 0.18% through February 29, 2020. Additionally, the Adviser has contractually agreed to limit the Fund's operating expenses, excluding interest expense (if any), to 0.28% and 0.53% for the Institutional Class and Administrative Class, respectively, through February 29, 2020. Only the Fund's Board of Trustees may modify or terminate this agreement.

Represents the average daily dividends for 30 days, assuming all dividends are reinvested, annualized by 365 days and divided by the net asset value per share at the end of the period. Reflects reimbursements or fee waivers currently in effect.

Represents the average daily dividends for the last seven days, assuming all dividends are reinvested, annualized by 365 days and divided by the net asset value per share at the end of the period. Reflects reimbursements or waivers of fees currently in effect.

Average annualized income dividend over the last seven days. Reflects reimbursements or waivers of fees currently in effect.

Represents the average daily dividends for 30 days, annualized by 365 days and divided by the net asset value per share at the end of the period. Does not reflect reimbursements or fee waivers currently in effect.

Subject to a contractual management fee waiver and an expense limitation agreement, excluding interest expense, if any, through February 29, 2020.

The management fee rate is 0.75% on assets up to $12 billion and 0.65% on assets in excess of $12 billion. The Adviser has contractually agreed to reduce the management fee to 0.63% on assets between $24 billion and $36 billion, and to 0.58% on assets between $36 billion and $48 billion and 0.57% on assets over $48 billion through February 28, 2019. In addition, the Adviser has contractually agreed to further waive a portion of its management fee such that the Fund's operating expenses, excluding interest expense (if any), are limited to 0.72%, 0.97%, 1.09% and 0.64% for the Institutional Class, Administrative Class, Investor Class and Retirement Class, respectively, through February 28, 2019. Only the Fund's Board of Trustees may modify or terminate this agreement.

Average annualized income dividend over the last seven days. Does not reflect reimbursements or waivers currently in effect.

The Fund's shareholders indirectly bear the expenses of the Institutional Class shares of the underlying Harbor funds (the Acquired Funds) in which the Fund invests. See the prospectus for further details.

Restated to reflect current fees.

Restated to reflect current fees.

Total annual fund operating expenses shown in this table will not agree to the expense ratio shown in the Financial Highlights table found in the prospectus because that ratio does not include the Acquired Funds' fees and expenses.

Subject to an expense limitation agreement (excluding interest expense, if any) through February 29, 2020

Reflects indirect expenses of the underlying Harbor funds.

Average annualized income dividend over the last 7 days. Reflects reimbursements or waivers of fees currently in effect.

Subject to a contractual management fee waiver through February 29, 2020